18 - Immunology Flashcards
What is the general idea of a vaccine?
organisms or pieces of them used to induce immunity
What are 3 types of vaccines?
- live attenuated vaccines
- inactivated killed vaccines
- subunit vaccines
Life attenuated vaccines
weakened pathogens, mimic infection - induces immunity
Inactivated killed vaccines
microbes have been killed - require booster/safer
Subunit vaccines
use antigenic fragments of microbe
Herd immunity
most of the population is immune/ not enough susceptible individuals to support epidemics
Are vaccines safe?
Yes
What is hypersensitivity?
response that is beyond normal (allergy) - individual has been sensitized to antigen
What are the 4 types of hypersensitivity?
- Type 1: anaphylactic
- Type 2: cytotoxic
- Type 3: immune complex
- Type 4: delayed hypersensitivity
Type 1 hypersensitivity
Anaphylactic
- < 30 minutes
- systemic/localized
- antigen causes IgE to be produced which binds to basophils and releases histamines
Type 4 hypersensitivity
delayed hypersensitivity
- 1+ day
- T cells and macrophages must migrate
- Transplant rejection, poison ivy, TB (chronic disease)
- Sensitized, memory T cells, re-exposed -> activate T cells, cytokines, inflammation
What is an autoimmune disease?